This study is designed as an open comparison of the clinical efficacy and safety of 1-alpha-acetylmethadol (LAAM) administered three times a week and daily methadone as maintenance medications over an eighty-week period within a comprehensive treatment program. Dosages will be flexible but not exceed 100 mg. The subject population will consist of two groups: 1) male patients who elect to continue on one of the two maintenance medications after having completed forty weeks of treatment in the initial SAODAP- LAAM study (IND 10-092) and 2) females with no reproductive capapcity who volunteer for LAAM plus an equal number who have reproductive potential and are assigned to methadone. Evaluations will be made by periodic monitoring of parameters that assess side-effects, tissue toxicity, medical and psychiatric changes and psychosocial functioning. Participating programs will report the data on standardized forms. Electroencephalograms will be recorded and compared by visual assessments and computerized period analysis.